Voss S D, Leary T P, Sondel P M, Robb R J
Department of Human Oncology, University of Wisconsin Clinical Sciences Center, Madison 53792.
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2428-32. doi: 10.1073/pnas.90.6.2428.
The interleukin 2 receptor (IL-2R) consists of at least two subunits, alpha and beta, both of which can bind interleukin 2 (IL-2). Recent studies have demonstrated the existence of a third subunit, a 64-kDa molecule termed IL-2R gamma chain, and have suggested that gamma chain functions to regulate the rate of IL-2 dissociation from the receptor. In the present report we have addressed whether the gamma chain modulates IL-2R affinity by contributing contact sites for IL-2 binding. Using reagents that allow the IL-2R complex to be immunoprecipitated through the IL-2 molecule itself, we demonstrate the existence of a stable IL-2-IL-2R gamma-chain complex. These studies thus establish that the IL-2R gamma chain directly contributes to the IL-2-binding site, consistent with the hypothesis that gamma chain influences IL-2R affinity through its direct interaction with IL-2.
白细胞介素2受体（IL - 2R）至少由两个亚基组成，即α亚基和β亚基，二者均可结合白细胞介素2（IL - 2）。最近的研究证实存在第三个亚基，即一个称为IL - 2Rγ链的64 kDa分子，并表明γ链的功能是调节IL - 2从受体上解离的速率。在本报告中，我们探讨了γ链是否通过提供IL - 2结合的接触位点来调节IL - 2R的亲和力。使用能够通过IL - 2分子本身免疫沉淀IL - 2R复合物的试剂，我们证实了稳定的IL - 2 - IL - 2Rγ链复合物的存在。因此，这些研究表明IL - 2Rγ链直接参与IL - 2结合位点的形成，这与γ链通过与IL - 2直接相互作用影响IL - 2R亲和力的假设一致。
